Portable information equipment, such as a tablet personal computer (tablet PC), is light-weight and compact for better portability, but often has limited functions. For example, a tablet PC typically does not come with multiple input/output (I/O) ports for connecting to external devices, a high-capacity battery, etc.
When an expansion unit is connected to a tablet PC, a user often holds the tablet PC that is attached to the expansion unit in a similar manner to holding a typical tablet PC without an expansion unit. With the above-mentioned configuration, the expansion unit is required to be securely attached to the tablet PC in order to prevent any type of rattling. Especially in the case of a tablet PC, since a tablet PC is thin at the lateral face, so a more stable and rigid attachment structure is required for an expansion unit to avoid rattling during normal usage.
The present disclose provides an expansion unit capable of being securely attached to a portable information equipment unit and without rattling.